well, I shall reply just to draw a line. I managed to do everything. So I created .xsession file with the following lines:
while true
do
xsetroot -name "`df -h / | awk 'END {print "root:" $5"|"}' | sed 's/Use%//'`
`df -h /home| awk 'END {print "home:" $5"|"}' | sed 's/Use%//'` `uptime |
awk '{print $1}'`"
sleep 55
done
and now it works very nicely. Thanks for your help
